Introduction: Sex hormone-binding globulin (SHBG) regulates the bioavailability of sex steroid hormones, which in turn regulate reproductive function. The potential association of SHBG gene polymorphisms with the age at menopause has not been examined.
Objective: The present study aimed to assess the possible relationship between the pentanucleotide (TAAAA)n repeat polymorphism in the promoter of the SHBG gene and the age at menopause in a Greek female population.
Methods: Two hundred and ten postmenopausal women aged 4663 years were included in the study. The age (year and month) at the last menstrual period as well as anthropometric parameters were recorded in all participants. Genotyping of the (TAAAA)n repeat polymorphism was performed by PCR.
Results: Genotype analysis revealed (TAAAA)n pentanucleotide alleles of 611 repeats. Regarding the allele with seven TAAAA repeats, the age at menopause was higher in carriers of this allele (50.2±3.1 years) than in non carriers (48.0±4.8 years, P=0.026). Furthermore, the age at menopause was lower in women carrying the allele with eight TAAAA repeats (47.5±4.8 years) than in women not carrying this allele (48.8±4.4 years, P=0.048). The associations remained significant after statistical adjustment for body mass index (BMI) and smoking (P=0.019 and P=0.043 respectively). No association of the other alleles with the age at menopause was detected.
Conclusions: Our results indicate that the (TAAAA)n repeat polymorphism of SHBG gene is associated with the age at menopause in Greek postmenopausal women. Additional studies are required to explore the biological importance of this SHBG polymorphism.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.